Lateral flow immunoassay (“IA”) test strips have been validated to rapidly and selectively detect analytes of interest, such as proteins, in plant material, such as corn leaf samples. Exemplary IA lateral flow strips are available from Agdia located at 30380 County Road 6 in Elkhart, Ind. 46514.
Manual methods have been used in the past to read IA lateral flow strips. The process begins with the receipt of sample tubes that are in a 12×8 matrix test stand. The sample tubes include plant material. The sample tubes are placed in a robotic system to read and store individual barcode information from the sample tubes. The samples are then processed (bead addition, buffer addition, capping tubes, grinding and de-capping tubes) to extract plant proteins. Subsequently, a 12 strip IA lateral flow strip comb has one finger or strip inserted into each sample in a given row. For a 12×8 matrix, eight 12 strip combs are needed.
The fingers of the IA strips are designed to provide a colored band a given location on the finger if the protein is present in plant sample. Each finger may include multiple potential bands at spaced apart locations, each of which being associated with a different protein. As such, a finger may be used to test for the presence of multiple proteins in the plant sample.
By way of example, a finger has a first location whereat a colored band will appear if a first protein is present in the plant sample the finger is exposed to and a second location whereat a colored band will appear if a second protein is present in the plant sample the finger is exposed to. Assuming the finger is exposed to a plant sample containing both the first protein and the second protein, a colored band is provided at both the first location and the second location. Assuming the finger is exposed to a plant sample containing neither the first protein or the second protein, no colored band is provided at either the first location or the second location. Assuming the finger is exposed to a plant sample containing the first protein but not the second protein, a colored band is provided at the first location but not the second location. Assuming the finger is exposed to a plant sample containing the second protein but not the first protein, a colored band is provided at the second location but not the first location.
After a five minute incubation, the combs are removed from the samples and manually read to determine the presence of one or more proteins in the respective samples. For the example above, an operator examines the fingers to see if a band is present at the first location or the second location. The presence or absence of a band is manually entered into a computer program that merges the information with the barcode information stored earlier. The combs may then be discarded.